Operation Stack is an emergency measure by Kent Police to manage the build-up of heavy goods vehicles on the M20 when services across the English Channel are disrupted. These disruptions could be from extreme weather, hazardous conditions (such as fire) at the Port of Dover, or civil action. Sadly, these occasions are increasingly likely.
The basic premise of Operation Stack is to use lanes of the M20 for freight to queue for journeys by tunnel and by sea vessel. The rest of the motorway, in both directions, is usually reserved for emergency traffic such as break down recovery and ambulances. This increases the number of parking spaces for lorries in Kent from a few hundred to over 3000.
The Port of Dover handles approximately 90% of freight traffic between the UK and mainland Europe, so any disruption involving the English Channel can very quickly affect the key motorways in Dover and the rest of Kent.
Last year, Highways England announced that they would soon have the option of using Manston Airfield to provide even more emergency relief when traffic towards Dover is heavily restricted. When there is still a limited amount of traffic able to cross into Calais, the waiting freight is classified according to the goods onboard. Quick to market goods such as chilled and perishable food are given priority, and Kent Police will usually allow at least some lorries carrying such inventory to pass through quickly.
Whilst Operation Stack is intended to make the situation as safe and controlled as possible, it would ultimately lead to a significant level of disruption. As well as freight companies with regular routes through Kent, tourists are advised to check with Highways England and/or a national traffic updates source if there is any doubt as to the accessibility of the M20 in Kent.